On Friday, Aug. 5, the launch window for NASA's Jupiter-bound Juno mission opens at 8:34 a.m. PDT (11:34 a.m. EDT) and extends through 9:43 a.m. PDT (12:43 p.m. EDT) at the Cape Canaveral Air Force Station in Florida. The satellite observatory is nestled inside the top of a United Launch Alliance Atlas V 551 rocket, the most powerful Atlas rocket in NASA's inventory.

The solar-powered Juno spacecraft will orbit Jupiter's poles 30 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere.

On launch day, Aug. 5, NASA TV commentary coverage of the countdown will begin at 6 a.m. PDT (9 a.m. EDT). The coverage will be webcast at http://www.nasa.gov/ntv .

Right after launch, the rocket will be airborne, carrying Juno up and over the Atlantic Ocean.
Solid rocket motors jettisoned -- occurs at about launch plus 106 seconds
The five solid rocket motors that have been providing some extra "get-up-and-go" for Juno's Atlas will complete their burn and be "stagger jettisoned." First, solids 1 and 2 separate from the rocket, followed 1.5 seconds later by solids 3, 4 and 5.

The Atlas's 68-footlong (21-meter-long) nose cone, or fairing, will separate and be jettisoned as planned, providing Juno and its Centaur upper stage with their first taste of exo-atmospheric existence. The Atlas V's 106.6 foot-long (33-meter-long) first-stage will have completed its tour of duty. The Centaur upper stage, which will provide the final kick for Juno, will begin the first of two scheduled burns.

Parking at 17,500 miles per hour -- occurs at about launch plus 10 minutes, 45 seconds

The Centaur upper stage will temporarily stop firing, as planned, and the rocket and Juno will begin a planned 30-minute coast phase, also known as a "parking orbit."